Electric lamp



FREDERICK G. KEYES, OF HOBOKEN, NEW' JERSEY, .ASSIGNOR T0 COOPER HEWITTELECTRIC COMPANY, 0F HOBOKEN, NEW JERSEY, A CORPORATION OF NEW TER- SEY.

Specification of Letters Patent.

ELECTRIC LAMP.

Patented lune 1W, 11919.

Original application filed January 8, 1914, Serial No. 811,003. Dividedand this application filed April 2, i

" 1915. Serial No. 18,674.

To all whom t may concern:

Beit known that I, FREDERICK G. KEYES, a citizen of the United States,and resident of Hoboken, county of Hudson, State of New Jersey, haveinvented certain new and useful Improvements in Electric Lamps, of whichthe following is a specification.

The present invention relates to improvements in tungsten lamps, moreparticularly lamps of that class having high candle power. lamps is atungsten filament of considerably larger diameter than is nowcustomarily ing the capacity indicated above, that is to used for thefilaments of constant potential tungsten lamps, the same bein connectedwith heavy iron lead wires. ith the arrangement thus described thepotential of tungsten lamps may be considerablv reduced,

while the current carrying capacity thereof, is correspondinglyincreased. The result isf.

that with the same expenditure of electrical energy a lamp having farless fragility than usualis provided and by reason of the lower appliedpotential, the lamp operates within a less limited sphere .and escapescertain of the limitations imposed by the usual commercial supplyvoltages.

In the commercial forms of filament lamp now in use, the largest valueof the current is about 2.5 amperes. In the metal lament lamps hererepresented, a current of over eighteen amperes may be utilized. Inspeaking hereinafter of heavy filaments or filaments of considerablediameter, the intention is to make such Aterms apply to filamentshavsay, capable of carrying current of above eighteen amp'eres. l

Whatever attempts have been made heretofore to produce lamps having thecharacteristics of the lampherein described have been defeated by thefailure of the seals which, in the usual form, are unable to sustaincurrents of the indicated magnitude for more than a brief period. l

Another feature of the lamp resides in the mode of securing the propersealing of the lead wires and of the anchors which support the tungstenfilament which in the present invention usually appears in the form of aspiral. i

lSpecial means are also provided for mak- Q ing stable connectionsbetween theisnds of the tungsten spiral and the iron leads and Thecentral feature of these novel' other details are present which will bedescribed in due course in the present specifica-1 tion.

My invention is illustrated in the accorritungsten spiral; Fig. 3 is adetail, also mainly in section, of the connection between an end of thetungsten spiral and one of the inner leads; and Fig. 4 is a bottom viewof the filament.

In thedrawings, lis a globe for one of myJ lamps and '2 is a tungsten'lament, here shown 1n the form of a spiral, located approximately at thecenter of the globe 1. The iilament is attached at its ends to leadwires 3, 3, of copper sheathed with iron, the

copper being utilized for its good 'conducting qualities and the ironbeing employed for its stilfness or rigidity to prevent the bending ordistortion of the copper wire under the infiuence .of the hightemperature developed within the globe. i

In Fig. 2 the copper conductor is shown at 20, land the ironsheathing-at 3. Iron anchor rods are shown at 4, 4, the v same beingprovided with tip portions 5, 5, of tung- `sten wire which are sealedt`o the iron rods within a tubular extension, 7, of the'globe l andbeing arranged just above `a shoulder, 8, near the bottom of saidextension. The object of the diaphragm 6 is to shut ofl from the tubularextension and from the lamp seals, presently to be described, near theupper end of said extension, all unnecessary heat. The diaphragm 6 doesnot necessarily .-5

leads 9, 9, which form mechanically a part of the seals of the lamp. Therods, 9, 9, pass through platinum tubes 10, constituting the mainconducting portion of the lamp seals. On the outer ends of the tubes 10,10, are placed iron caps 11, 11, which are Ywelded to the tubes 10, 10and the rods 9, 9, by means of an Oxy-acetylene ame. 'Ihe external leadsmay be copper wires 13, 13, fused or soldered to the caps 11, 11, asshown. 1'0 `It will be obserted that the seals are made within arentrant portion of the extension 7, `whereby the danger of fracture.from Inechanical causes is reduced. The tubes 10, 10,.A are sealedwithin the said rentrant, portiens. The entire interior of the lamp is"liu'sisealed off from exposure to the external air `and a structure isprovided which will admit of the safe and continuous application theretoof currents above eighteen amperes. In this way lainps of exceedinglyhigh candle power are obtainable without unduly shortening the life ofthe lamps.

The mode of connection between one of the inner leads 3, and thealuminum disk 6 2t is illustrated in Fig. 2. An ope-ning be ing made inthe diaphragm at the proper point the tube of copper and iron,surrounded by a tube 14k of quartz is passed through the diaphragm andthe entire inner '30 space is then packed with a suitable cement, 15,such as might be formed by the mixture of ground silica and sodiumsilicate. This preventsthe contact of the inner leads with the aluminumdisk and thus obviates the 95 danger of short circuiting between saidleads. By similar construction the anchor rods 4 are supported in thedisk and insud lated therefrom and from the inner leads 40 ,At the innerterminals of-the leads 3, 3, the iron coverings are attached to orformed into cups 16, 16, into which the ends of the tungsten spiralextend and within which they are attached to the said cups or weldedthereto so as to form-good electrical connection therewith. As a meansfor joining the heavy copper leads 9, 9, to the inner leads 3, 3,through the medium of the sockets 12, 12, I may make use of any suitablesort of juncture.`

For example, I may extend ,the lower ends of the leads 9, 9, down intothe socket 12, 12, and hold them there by means of set screws 17,17.

This application is a division of my application Serial Number 811,003,filed January 3th, 1914,.

I claim as my invention: 1. In an electric device, a container, a

conductor located within the container, leads connected with theterminals of the conductor and sealed in the wall of the container, andmeans independent of the seals filament.

for carrying the Weight of the conductor, said means consisting of adiaphragm c5 mounted in said container and anchor rods extendingtherefrom and connected to said conductor.

2. In an electric device, a container, a concentrated filament ofconducting material located within the container, leads connected withthe terminals of the filament and sealed in the wall of the container,and means independent of the seals for carrying the vweight of thefilament, said means con- 7a sisting-of a diaphragm mounted in saidcontainer and anchor rods extending therefrom and connected to saidfilament.

3. In a tungsten lamp, a` container, a filament of tungsten locatedwithin the container, leads connected with the terminals of the filamentand sealed in the wall of the container, and means independent of theseals for carrying the weight of the filament, said means consisting ofa diaphragm mounted in said container and anchor rods extendingtherefrom and connected to said filament. Y

4. In anelectric device. a container, a filament of conducting materiallocated within 99 the container, tubular seals connected with theterminals of the filament and sealed in the wall of the container, andmeans indei pendent of the seals for carrying ,the weight of thefilament, said means consisting of a diaphragm mounted in said containerand anchor rods extending therefrom and connected to said filament.

5. In a tungsten lamp, a container, a fila ment of tungsten locatedWithin the container, tubular seals connected with the terminals of thefilament and sealed in the wall of the container andmeans .independentof the seals for carrying the weight of the filament, said meansconsisting of a diaphragm 105 mounted in said container and anchor rodsextending therefrom and connected to said extending therefrom andconnected to the filament.

Signed at New York in the county of `New York and State of New York this31st day 1'20 of March, A. D.. 1915.

FREDERICK G. KEYES.

VitnesSeS:

, IVM. H. CAPEL,

HAROLD B. VVooDwARD.

